1. Field of the Invention
The present invention relates to method and means for manufacturing wire cable for torque transmission application and more particularly but not by way of limitation to a method and means for producing cable using preformed spring stock for the wrappings.
2. History of the Prior Art
There is widespread use of wire wound torque transmission cables where it is desirable to induce rotary motion at a remote location from the rotary power source. Normally, such cables are manufactured by various processes and apparatus which wrap a plurality of wires onto either a solid or hollow flexible mandrel. If it is desired that the finished product be a solid torque transmitting cable, the mandrel is usually flexible and becomes a part of the finished cable.
On the other hand, if the torque transmitting cable is to be hollow, the mandrel must either be removed after the winding process or the mandrel must be flexible and also hollow.
After the wrapping process about a mandrel is done, it is extremely difficult to remove the mandrel from the finished product. Further there is a tendency for the wire after it has been wrapped to spring open if either end is released.
Heretofore, the general method of removing the mandrel is to allow the winding to spring open to a certain extent. While this allows easy removal of the mandrel, it changes the size of the finished torque transmission cable which gives rise to obvious quality control problems in both sizes. Another problem associated with such cables is that of internal stress present between successive layers of windings which tend to decrease the efficiency of torque transmission and the life of the cable. There has also been a problem associated with the winding of very small wire by the prior art methods.